JPH02217817A - Target plate - Google Patents

Abstract

PURPOSE:To obtain an invariably effective target contrast even at low outside temperature or in the absence of sunshine irradiation by coating a reticle part with a paint, and feeding electricity to the reticle part and generating heat. CONSTITUTION:An insulating plate 5 is stuck on the background part 2 where a reticle is drawn and the conductive paint is applied thereupon to form the reticle 3. Electrodes 4A-4D for feeding electricity to the conductive paint are fitted on four end surfaces of the reticle 3. Here, when the electric resistance values between the four electrodes 4A-4D and intersection part 6 are equalize to one another, currents flowing through respective reticle parts can be set at the same position and the reticles can be observed with equal brightness. Consequently, the contrast of the target of an infrared image pickup device can be increased regardless of the outside temperature and sunshine irradiation to improve the performance of an infrared image pickup and collimation system and reduce the contrast.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Minute Hand] This invention relates to an improvement of a target plate for use outdoors in an infrared imaging device.

[Conventional technology]

FIG. 5 is a diagram showing a conventional target plate used for the above purpose, in which (1) is a reticle portion and (2) is a background portion.

In conventional devices, in order to obtain as high a contrast between the reticle portion (1) and the background portion 01 as possible when viewing the target with an infrared imaging device, the reticle portion (1)
The background part (2) was coated with an infrared high emissivity paint, such as a black matte paint, and the background part (2) was coated with an infrared low emissivity paint, such as a white paint. With such a target plate, when the outside temperature is relatively high (20°C or higher), or when the target plate is relatively heated by sunlight, the infrared emissivity difference will be compensated for. The difference in the amount of infrared radiation can be obtained.

The reticle can be observed with good contrast and high brightness.

[Problem to be solved by the invention]

However, when the outside temperature is low and sunlight cannot be irradiated, the temperature of the target plate itself does not rise much, and the difference in the amount of infrared radiation between the two becomes small, resulting in a significant decrease in contrast. However, there was a problem in that it was difficult to visually recognize the image using an infrared imaging device.

This invention is intended to solve these difficulties,
The objective is to always obtain effective target contrast even at low outside temperatures or under no solar irradiation.

[Means to solve the problem]

In order to solve the problem, the present invention uses a means for applying conductive paint to the reticle portion and applying electricity to the reticle portion to generate heat in the reticle portion. In another invention, the target plate is box-shaped and includes means for blowing hot air onto the target plate to maintain the temperature of the target plate at a high temperature at all times.

In yet another invention, the background portion has a high infrared reflectance and is provided with means for slanting the background portion so that the sky can be reflected and viewed from the infrared image carrier.

[For production]

With the above means, it is possible to always maintain a high contrast between the reticle portion and the background portion regardless of the outside temperature or solar irradiation, and it is possible to improve the visibility of the target by the infrared imaging device.

〔Example〕

FIG. 1 is a diagram showing an embodiment of the invention in which a conductive material such as a metal plate is used for the target plate, and (3) shows a reticle,
(4A) to (4D) are electrodes, and (5) is an insulating plate.

In Figure 1, the background part (2) of the part where the reticle is drawn is shown.
First, an insulating plate (5) is attached, and a conductive paint is applied thereon to form a reticle (3). Reticle (
Electrodes (4 people) to (4D) for energizing the conductive paint are attached to the four end faces of 31.

FIG. 2 is a diagram showing a circuit in a state in which 1.1 electrodes (4A) to (4D) are energized, and (6) is a reticle intersection part,
(7) is a battery. As you can see from the @ path in Figure 2.

By making the electrical resistance between the four electrodes (4A) to (4D) and the intersection part (6) equal, it is possible to make the current flowing through each reticle part the same value.2IEIM the reticle with equal brightness. can do.

The above example shows the case where a metal plate is used as the background plate, but if the background plate is made of a non-conductive material, the insulating plate (5) is removed and the reticle (3) is directly applied to the background part (21). I can do it by doing something.

FIG. 3 is a diagram showing an example of the configuration according to another embodiment, in which (8) is a box-shaped target, (9) is an air duct opening, α [is an exhaust duct opening, 01) is a hot air, and ■ is a It's exhaust.

In Figure 3, the reticle part (1) and the background part (2)
is the same as the conventional device, and the hot air θ1) is sent from the lower air duct opening (9) in a box shape so that a constant amount of infrared radiation difference can be obtained regardless of the outside temperature or the amount of solar irradiation. Target (8
], and the exhaust gas (Φ is exhausted from the upper exhaust duct port a1. As a result, the surfaces of the reticle part (11 and background part (2) can always be kept above a certain temperature, and the red It is possible to maintain the external contrast in a good condition.

FIG. 4 is a diagram showing an example of the configuration of still another embodiment, in which @ represents an inclined background portion, and (2) represents a reticle holding portion.

The surface of the inclined background part (■) is, for example, maintained in a mirror-like state or a highly reflective state close to this, and is inclined at an angle at which the sky is reflected when viewed from the line of sight of the infrared imaging device. . The reticle part (January) is coated with high infrared emissivity paint and is installed almost perpendicular to the line of sight.The reticle holding part (b) holds the vertical reticle part (1). Generally, the sky is observed to be as low as -20°C to -40°C when measured in the infrared region on clear skies, regardless of day or night, and even on cloudy days, the sky is observed to be as low as -20°C to -40°C. As a result of observing the temperature (~0°C), the above-mentioned sky temperature is measured as the temperature of the inclined background part (2), and even if the conventional reticle part (1) is used, it is not possible to measure the target with sufficient contrast. can.

In the embodiment shown in FIG. 4, the reticle part (1) is fixed by the reticle holding part (2), but the present invention is not limited to this. Needless to say, it may be moved with respect to the inclined background part (2).

〔Effect of the invention〕

As described above, according to these inventions, it is possible to increase the contrast of the target of an infrared imaging device regardless of the outside temperature or solar irradiation. Since it can be realized much more cheaply, it can greatly contribute to improving the performance and reducing the cost of infrared imaging and targeting systems.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of one embodiment of the present invention. FIG. 2 is a diagram showing a circuit state of the invention, FIG. 3 is a diagram showing another embodiment of the invention, and FIG. 4 is a diagram showing still another embodiment, in which (1) is a diagram showing a reticle section. . (2) is the background part, (3) is the reticle, (4^) ~ (4D
) is an electrode. (5) is an insulating plate, (8) is a box-shaped target, and (9) is a ventilation duct opening. a [ is the exhaust duct opening, ■ is the inclined background part. Note that the same or corresponding parts are indicated by the same reference numerals.

Claims (4)

[Claims] (1) A non-conductive background plate that has been subjected to a surface treatment with low infrared emissivity, and a conductive coating area that has been applied to the reticle display area on the background plate and has been subjected to a surface treatment that has high infrared emissivity; A target plate comprising a plurality of electrodes for passing a current of substantially uniform current density through the conductive coating area. (2) A conductive background plate that has been subjected to a surface treatment with low infrared emissivity, an insulating plate that is installed in the reticle display area of the background plate, and a conductive background plate that has been subjected to a surface treatment that has a high infrared 1. A target plate comprising: a conductive coating area subjected to an emissivity surface treatment; and a plurality of electrodes for passing a current with a substantially uniform current density through the conductive coating area. (3) A box-shaped structure having a background portion subjected to a surface treatment with low infrared emissivity, a reticle portion displayed on the background portion and subjected to a surface treatment with high infrared emissivity, and the box A target board comprising: a hot air intake provided below the box-like structure; and an exhaust port provided above the box-like structure. (4) A background part that has been subjected to a surface treatment with high infrared reflectance and is installed at an angle that allows the sky to be reflected when viewed from the visual line; and a reticle section installed at a position substantially perpendicular to the line of sight with the reticle section in the background.